Boiler



April 3, 1934 J. c. wlLLcox 1,953,667

BOILER Filed Deo. 5. 1932 2 Sheets-Sheet l pril 3, 1934. J. C, WILLCOX L95367 BOLER Filed Deo. 5. 1932 2 Sheets-Sheet 2 J0@ @i Mliemf Patented Apr. 3, 1934 STATES 2 Claims.

My invention provides an improved boiler. Boilers of fairly high emciency for use in burning coal have hitherto been produced, but such boilers have been found very inemcient and wasteful of fuel and heat energy, when used with oil burners or the burning of gas. My improved boiler has been designed especially to obtain in a boiler of simple and durable construction, the greatest possible efficiency in the burning of oil, gas or pulverized coal, but incidentally, in thus improving the burner, the eiciency for burning coal or fuels is also increased. In fact, the irnproved boiler also has a high efficiency in the burning of coal in connection with forced draft stokers, or generally in the burning of solid fuel in connection with forced draft. The improved boiler is capable of various embodiments, but a very highly efiicient form thereof is illustrated in the accompanying drawings, wherein like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. 1 is a vertical section taken from front to the rear centrally through the complete boiler;

Fig. 2 is a transverse vertical section taken on the line 2 2 of Fig. 1; and

Fig. 3 is a transverse vertical section taken on the line 33 of Fig. 1.

The improved boiler is Water-jacketed by Water legs that extend at the sides, ends, top and preferably at the bottom thereof, and the re box or fuel chamber is divided into primary and secondary combustion chambers by an intermediate water leg over which the flames must move in passing from the primary to the secondary combustion chamber. Inclined water tubes extend through the primary and secondary combustion chambers and connect opposite sides or walls of the water jacket. In connection with the primary combustion chamber, there is fuel-inlet means arranged to cause the initial combustion to take place at the bottom of said primary combustion chamber; and at the lower portion of the secondary combustion chamber there is an outlet for the products of combustion that lead to the stack. Such arrangement causes the flames or products of combustion to travel upward between the tubes in the primary combustion chamber and downward between the tubes in the secondary combustion chamber with highly improved action which will be later more fully considered.

Referring now particularly to the boiler illustrated in the drawings. The outer shell of the boiler is indicated by the numeral 4, and the inner shell thereof by the numeral 5. These shells are spaced to form a water jacket, at the sides, ends, top and bottom of the inner shell; and said'inner shell is provided with spaced vertical plates that form an intermediate water leg 6 that divides the fire box into a primary combustion chamber ct and a secondary combustion chamber b. The water leg 6 opens at its bottom into the lower portion of the water jacket and at the sides into the sides of said water jacket. The top of the water leg 6 extends well toward the crown of the inner shell 5 at the sides thereof, but is formed with a flame passage 7, preferably V-shaped, that permits the flames or products of combustion to quite freely pass from the primary to the secondary combustion chamber.

in this preferred form of the boiler, there is a novel arrangement of water tubes 8. The water tubes 8 in the primary combustion chamber a are inclined preferably at a very considerable angle to horizontal, as best 'shown in Fig. 2, the inclination there shown being from the right toward the left. These tubes connect the opposite sides of -the water leg of the boiler. Here it should also be noted that the flame passage 7 extends well above the uppermost of the said water tubes.

The water tubes 8, in the secondary combustion chamber b like the tubes 8 of the primary combustion chamber a, connect the opposite sides of the water leg of the boiler, but the inclination is reversed from those of the tubes of the primary combustion chamber, and as illustrated in Fig. 3, the inclination is from the left toward the right. Also it will be noted that the flame passage 7 extends well above the uppermost of the tubes of said secondary combustion chamber. The importance of this relative arrangement of tubes will be discussed in the description of the operation. Attention is now directed to the cross-sections of the tubes 8, as shown in Fig. l. It will be noted that said tubes are in staggered arrangement with comparatively small spaces between the tubes of different rows and with spaces ofV considerable extent between each group of four adjacent tubes. The importance of this will also be discussed in the description of the operation.

The hot water outlet pipes 9 extend from the top of the outer boiler shell l and the cold Water return tubes 10 extend from the lower portion of one of the end plates of said outer shell, as best shown in Fig. 1. The boiler illustrated is designed as a hot water boiler but if designed as a steam boiler, the crown. of the outer shell 4 would lation through the boiler.

be raised, so as to ailord a steam dome in which the water level will be maintained approximately at the altitude of the top of the outer shell 4, here shown.

The boiler now illustrated is shown as arranged for the ready application of an oil burner and hence is shown as provided with quite large fuel inlet means in the form of a tube l1 set into the front wall and arranged to guide the burner or direct the flame therefrom into the lower portion of the primary combustion chamber a, below the tubes 8 of said chamber. The numeral l2 indicates a stack, the lower end of which, as shown is turned horizontally and opens from the lower portion of the secondary combustion chamber b. From the rear upper portion of the secondary combustion chamber b, an auxiliary outlet tube 13 leads into the stack l2. This auxiliary outlet 13 is arranged to be ordinarily closed by a damper 14.

In the illustration given in the drawings, the entire boiler is set upon a base l5 and the entire boiler including the bottom thereof, is shown as covered with a heavy insulation 16. Some types of burners require a passage in the bottom of the combustion chamber for the entrance of nozzle or fuel-delivery end thereof and hence I have shown the water jacketed bottom of the boiler as provided with tubular cut-out 1'?, which in the drawings, is filled with insulating material and covered by a removable plate 18. The sides of the outer burner shell 4 are formed with large openings normally closed by detachable plates 19 secured by screws, bolts or otherwise and which when removed, afford access to the tubes so that they may be readily cleaned. Advisably, portions of the insulation 16a of the insulation 16 are made removable with the plates 19.

It will be noted that in the bottom of the water leg of the boiler is a spacing lug 20 that spaces and supports the inner shell 5 from the outer shell 4.

Operation For the purpose of illustration, it will be assumed that from a suitable oil burner a blast burning oil is being discharged into the bottom or lower portion of primary combustion chamber 8. This blast, of course, produces a forced circu- The flames initially introduced into the bottom of the primary combustion chamber will be carried upward against and between the tubes of said primary combustion chamber and from thence they will be drawn through the passage '7 of the intermediate water leg and from thence will be drawn downward against and between the tubes of the secondary combustion chamber and outward into the lower end of stack l2. In the above statement, it is assumed that the damper 14 is closed. Said damper will be closed during the normal operation but is arranged to be opened to give more direct passage of llames to the stack when 4the burner or the re is first started. The flames and products of combustion, in passing as above described, contact with all of the walls of the primary and secondary combustion chambers and with the walls of the intermediate water leg. In passing from one row of tubes to the other, the llames are caused to take a zigzag course which insures a turbulence of flames and complete contact with all of the tube surfaces. Moreover, as the llames pass into the spaces between each group of four adjacent tubes, there will be a sort of cyclonic turbulence produced which not only insures most complete combustion but the maximum heat absorption through the tubes.

The oblique arrangement of the tubes is highly desirable because it accelerates the movement of the water through the tubes. The flames in passing through an inclined group of tubes, will be drifted slightly to that side which is at the high end of the tubes and hence it is highly important that the tubes in the two or several combustion chambers be in reverse oblique arrangement so that the drift in the one chamber will be offset by the drift in the other.

The intermediate water leg which divides the re box into primary and secondary combustion chambers, of course, affords a baille which causes the flames and products of combustion to move upward between the tubes of the primary combustion chamber and downward between the tubes of the secondary combustion chamber.

What I claim is:

l. A boiler comprising a water-jacketed substantially rectangular shell having a transverse partition terminating short of the top thereof and dividing the same into primary and secondary combustion chambers, a group of transversely inclined water tubes in each of said combustion chambers connecting the water-jacketed sides thereof, the tubes in the primary combustion chamber inclining in one direction, and the tubes in the secondary combustion chamber inclining in the opposite direction, and an outlet for the products of combustion opening from the lower portion of said secondary combustion chamber at a point below the tubes of said chamber, whereby the products of combustion are caused to pass upward between the inclined tubes of said primary combustion chamber and to travel downward between the inclined tubes in said secondary combustion chamber.

2. The structure dened in claim l in which said secondary combustion chamber has a valveequipped normally closed auxiliary outlet for the products of combustion, leading from its upper portion, whereby under certain conditions, part of the products of combustion may be carried off without passing between the water tubes of said secondary combustion chamber.

JAY C. WILLCOX. 

